tools/target_dec_fuzzer: Adjust threshold for PIXLET

Fixes: Timeout
Fixes: 425754611/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PIXLET_fuzzer-4778526102585344

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

tools/target_dec_fuzzer.c

@@ -286,6 +286,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     case AV_CODEC_ID_MXPEG:       maxpixels  /= 128;   break;
     case AV_CODEC_ID_NUV:         maxpixels  /= 128;   break;
     case AV_CODEC_ID_OPUS:        maxsamples /= 16384; break;
+    case AV_CODEC_ID_PIXLET:      maxpixels  /= 1024;  break;
     case AV_CODEC_ID_PNG:         maxpixels  /= 128;   break;
     case AV_CODEC_ID_APNG:        maxpixels  /= 128;   break;
     case AV_CODEC_ID_QTRLE:       maxpixels  /= 16;    break;